1. Field of the Invention
This invention relates generally to a color video camera apparatus comprising a solid-state image sensor with a complementary color mosaic filter and, more particularly, to a variable color matrix circuit for use in such a video camera apparatus to obtain a higher color fidelity.
2. Description of the Related Art
In the conventional color video camera apparatus with a single CCD image sensor, a complementary color mosaic filter is generally used for generating two color difference signals in addition to a luminance signal. For example, in the case where a complementary color mosaic filter with four colors Ye, Mg, Cy and Gr is used (where Ye represents yellow, Mg magenta, Cy cyan and Gr green), adjacent odd-numbered and even-numbered horizontal lines are simultaneously read to alternately produce (2R-G) and (2B-G) color difference signals in an odd-numbered field. In an even-numbered field, adjacent even-numbered and odd-numbered horizontal lines are simultaneously read to alternately produce (2B-G) and (2R-G) color difference signals. Two concurrent color difference signals (2B-G) and (2R-G) are obtained from the above alternate color difference signals by means of line delay circuits and switches. The thus obtained color difference signals are then subjected to the following matfixing operation to produce (R-Y) and (B-Y) color difference signals which can be used to produce a standard color composite signal. EQU R-Y=2R-G+a(2B-G) EQU B-Y=2B-G+b(2R-G)
where a and b are predetermined constants or matfixing coefficients.
The inventor found that the above matfixing operation is not satisfactory enough to obtain a higher color fidelity.